1. Field of the Invention
The present invention relates to a deformation element of a rail-borne vehicle which is disposed in the region of at least one deformation zone located on the end side of the vehicle and comprises at least one tubular hollow space.
2. Description of the Prior Art
For financial reasons and reasons relating to safety technology, deformation zones are usually provided in the region of the ends located on the longitudinal side of a rail-borne vehicle. On the one hand, this serves to obviate or reduce any damage to the vehicle in the event of an accident, on the other hand vehicle passenger safety is thereby increased. The parts of a rail-borne vehicle which are most frequently directly involved in accidents are the front and rear carriage end region, since most accidents are rear end collisionsxe2x80x94in the case of a train consisting of several coupled carriages individual carriages can collide together in an accidentxe2x80x94or are head-on collisions involving other traffic participants or obstacles.
Therefore, in order to protect a rail-borne vehicle tubular deformation elements which can be compressed and folded in the event of a sufficiently strong force effect are integrated in the prior art into the front and mostly also into the rear vehicle face. This feature serves to use up some of the kinetic energy, which acts upon the vehicle, for the deformation of the deformation element. Reducing the kinetic energy in this way serves also to reduce the loading which acts upon the rest of the rail-borne vehicle.
By reason of the substantial intrinsic weight and the associated high kinetic energy of the rail-borne vehicle, it is still possible for extremely high peaks of force to occur during accidents. For this reason it is advantageous to introduce the respective loading into a deformation element at a low trigger force over the largest possible area and to distribute it over same.
Typically, the attempt is made to solve this problem in that mutually separately installed deformation elements, which are designed as straightforward tubular hollow bodies mostly having an approximately square cross-section, are integrated in parallel adjacent to each other into the vehicle face, wherein the longitudinal sides of the deformation elements are disposed in parallel with respect to the direction of travel. Conventionally, these deformation elements are affixed in the head regions of the vehicle underframe and are connected together by means of a transverse beam acting as a bumper. The entire vehicle""s deformation characteristic to be achieved determines how many deformation elements are used and whether these deformation elements are installed at only one or both ends of a carriage.
U.S. Pat. Nos. 5,630,605 and 5,715,917 describe a method of reducing the energy released in the event of a collision by means of a impact-shock transmission element which is guided in such a manner as to be movable in a frame in the direction of travel, and a shock-absorbing honeycomb structure which can be compressed by means of the impact-shock transmission element.
FR 2 140 937 describes a front end region of a rail-borne vehicle which is disposed on both sides of a housing of an automatic coupling a corrugated metal sheet [sic]. This metal sheet is welded both to the coupling housing and also to the longitudinal and transverse beams of the rail-borne vehicle and forms a part of the vehicle structure, for which reason the replacement of this metal sheet in the event of a deformation is associated with substantial operational effort and financial cost.
EP 0 612 647 A1 discloses a railway carriage having a deformation element which is formed from a corrugated metal sheet and likewise forms a part of the vehicle structure, so that the replacement of the metal sheet is also associated in this case with substantial operational effort.
Furthermore, a disadvantage of the known devices is that by reason of the design undesirably high force peaks can nevertheless occur before the deformation elements fold. By virtue of these very high force peaks now and again, a large portion of the occurring loads can be transmitted to the passenger compartment. In order to prevent damage to the rail-borne vehicle or to prevent injury to vehicle passengers in the event an accident, the remaining vehicle structure must therefore be designed to be more robust and heavier, which has a detrimental effect upon the useful load. Furthermore, the relatively high costs in producing conventional deformation elements is disadvantageous. The replacement of damaged deformation elements is also associated with substantial operational effort.
Therefore, it is an object of the invention to provide a deformation element which can be produced conveniently and cost-effectively and which has a low trigger force, wherein it is possible to introduce force over a large area and the said deformation element can also be replaced in a convenient manner.
This object is achieved in accordance with the invention by virtue of the fact that the deformation element is attached in a replaceable manner in the rail-borne vehicle and is formed from two metal sheets, of which at least one is designed as a profiled metal sheet, which are connected together on mutually facing cross-pieces which lie against each other thus forming hollow boxes extending in parallel with each respect to each other.
In the case of the deformation element in accordance with the invention, the metal sheets lying one on top of the other serve to form tubular hollow spaces which can be compressed in the event of an accident, wherein any damaged deformation elements can be replaced by new ones.
It is an object to provide a deformation element which renders it possible to cover and protect a larger width of the vehicle face continuously. In the event of an accident this feature substantially enables the force to be introduced into a deformation element according to the invention over a larger area than in the case of the known deformation elements, whereby the occurring force peak can be reduced substantially. A further significant advantage over the known deformation devices is evident the convenient and cost-effective manufacture.
In order to provide for the deformation element a holding device which guarantees ease of replacement, one advantageous embodiment relates to the metal sheets being held in a frame.
Connecting the two metal sheets in a tried and tested manner in practice ensures that the two metal sheets lying one on top of the other are welded together at points on their contact surfaces.
For reasons relating to cost and production, the method of welding the metal sheets at points is preferred over other possible connection methods, such as e.g. welding the two metal sheets by means of a fillet weld over their entire length or by means of a screw-connection.
In order to obtain the most effective possible deformation characteristics, the hollow boxes comprise a hexagonal cross-section.
In order to protect the largest possible area of the width of the vehicle and to allow the introduction of force over a large area into the deformation element, the metal sheets extend substantially over the entire width of the rail-borne vehicle.
In one advantageous embodiment of the invention, the frame comprises two side parts and a front part, wherein the front part has a box-shaped transverse beam which extends substantially over the entire width of the vehicle, wherein the side of the transverse beam remote from the rail-borne vehicle is provided with ribs, in order in the event of a collision with a second rail-borne vehicle to prevent the transverse beam of a rail-borne vehicle from sliding over the other and damaging unprotected regions of the vehicle.
One advantageous embodiment of attaching the beaded metal sheets in the frame is to weld the beaded metal sheets to the frame.
The assembly and removal of the deformation element is facilitated by virtue of the fact that the side parts of the frame can be inserted via guide rails into longitudinal beams of the rail-borne vehicle.
One embodiment of considerable practical use demonstrates that the side parts of the frame are releasably connected with the aid of clamping connections to the longitudinal beams of the rail-borne vehicle.
In one advantageous embodiment, the clamping connection can comprise four mutually displaceable wedges.
In an advantageous manner, two wedges are rigidly connected to a plate.
Furthermore, in the case of this embodiment, one wedge is rigidly connected to bars which each comprise a thread.
In order to fix the clamping connection, it is provided that a wedge can be attached to the rods via the threads by means of nuts.